Harmonizer Recommends a Very High Speed
Open full view...Categories: Using VP Harmonizer
For example:
The Material is 1018 steel and the maximum speed of the machine is 12,000 RPM. The current condition is 1990 RPM and in chatter. You record the chatter with Harmonizer and it returns a speed of 10,218 RPM or 1685 SFM (cutter is 0.630" diameter), far in excess of the manufacturer's recommended surface speed limit of 500 SFM. The solution is to go back to the original settings, convert the 500 SFM to RPM, in this case 3032 RPM.
Change the Maximum Spindle Speed to 3032 RPM and rerun the test.
Harmonizer returns a stable speed of 2543 RPM.
TIP: In Harmonizer the Max Spindle Speed is not always the maximum speed of the spindle, but rather the maximum allowable speed for the tool and material you are testing.
Why can't we see a stability lobe diagram?
The stability lobe diagram (SLD) is a snapshot of the available stable speeds and axial depths of cut for a particular radial width of cut. Should the width change, the SLD must be recalculated and replotted. In addition, up to ten limits, such as, resonance, bending moment, torque, power and thermal must be applied to the SLD by our engineers as they analyze the DC kit measurements. The resulting Dashboard has the SLD and all of the limits embedded. It does the recalculations automatically and in realtime as parameters are changed. It also adjusts for changes in feed rate.
Here are some other differences:
• Dashboards determine stable depths and widths of cut, in addition to chatter free speeds.
• Dashboards allow feed rate optimization and calculates chip thinning.
• Dashboards take into account the machine's torque and power curve limits when selecting a speed, feed rate and depth of cut.
• Dashboards predict resonate frequencies and corresponding speeds to avoid (the full version of Harmonizer predicts resonance).
• Dashboards calculate tool costs and productivity.